Predicted to enable GTP 3',8'-cyclase activity and cyclic pyranopterin monophosphate synthase activity. Involved in inter-male aggressive behavior. Predicted to be active in mitochondrial matrix. Is expressed in several structures, including adult brain; embryonic/larval mushroom body; ganglia; imaginal disc; and synaptic neuropil domain. Human ortholog(s) of this gene implicated in molybdenum cofactor deficiency type A. Orthologous to human MOCS1 (molybdenum cofactor synthesis 1).